* PM's ruling bloc set for majority in upper house election
* Japan ruling bloc with allies has shot at 2/3 of upper house Constitution revision at stake in upper house poll
Prime Minister Shinzo Abe's ruling bloc is set to keep a solid majority in Japan's upper house election on Sunday and with allies could seal the two-thirds majority needed to keep alive his dream of revising the pacifist constitution, an NHK exit poll showed.
Abe's Liberal Democratic Party (LDP) and its junior partner, the Komeito party, will take 67-77 of the 124 seats being contested in parliament's 245-seat upper house. That, together with uncontested seats, assures them a majority.
Still up in the air, however, is whether the ruling bloc and its allies will keep the two-thirds "super majority" needed to begin the process of revising the constitution's pacifist Article 9 to further legitimise the military, a controversial step.
To maintain that majority, pro-revision forces need to win 85 seats. NHK's exit poll said they would take 76 to 88 seats.
The charter has not been amended since it was enacted in 1947 and changing it would be hugely symbolic, underscoring a shift away from post-war pacifism already under way.
Article 9, if taken literally, bans maintenance of a military but has been stretched to allow armed forces for self-defence.
Surveys show voters are divided over changing it, with opponents worried doing so would increase the risk of Japan getting entangled in U.S.-led conflicts.
Abe, who took office in December 2012 pledging to restart the economy and bolster defence, is pushing his LDP-led coalition as the best bet for political stability.
Opposition parties have focused on voters finances, including a potential hit on spending from an October rise in the sales tax to 10% and strains in the public pension system in the shrinking, fast-ageing population.
Aided by a fragmented opposition and low turnout, Abe has led his party to victory in five national elections since returning as LDP leader in 2012. He will become Japan's longest-serving premier if he stays in office until November.